package com.lrc.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.lrc.reggie.common.BaseContext;
import com.lrc.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 过滤器
 * 检查用户是否登录
 */
@Slf4j
@WebFilter(filterName = "LoginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {

    // 路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    // 过滤方法
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        // 1,获取本次请求的URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}",requestURI);

        // 定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                //对用户登陆操作放行
                "/user/login",
                "/user/sendMsg"
        };

        // 2,判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        // 3,如果不需要处理，这直接放行
        if (check){
            log.info("本次请求不需要处理：{}",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        // 4-1，判断是否是登录状态，是则放行
        if (request.getSession().getAttribute("employee") != null){
            log.info("用户以登录，用户id为：{}",request.getSession().getAttribute("employee"));

            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request,response);
            return;
        }

        //4-2、判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user") != null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }

        // 5,如果为登录，则返回为登录结果，通过输出流方式向客户端响应数据
        log.info("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match){
                return true;
            }
        }
            return false;
    }
}
